Brig. Gen. Jeffrey Sinclair leaves the courthouse March 4 after a day of motions before his trial at Fort Bragg, N.C. / James Robinson, AP

by Gregg Zoroya, USA TODAY

by Gregg Zoroya, USA TODAY

Prosecutors have agreed to drop sexual-assault charges against one of the highest-ranking military officers ever to face such allegations in an agreement under which the defendant will plead guilty to lesser offenses, according to defense attorneys.

After a judge last week ruled that a prosecution decision to seek trial against Army Brig. Gen. Jeffrey Sinclair, 51, was tainted by political considerations, the proceedings were suspended and a new round of plea negotiation commenced.

Maj. Gen. Clarence Chinn, a commanding officer stationed at the Fort Bragg Army post in North Carolina, agreed Saturday to accept Sinclair's guilty plea to lesser charges, including mistreatment of the female captain who accused him of sexual assault, according to plea agreement documents provided by defense lawyers. Sinclair also said he would admit to charges of using profanity and misusing a government credit card.

He had earlier pleaded guilty to three lesser charges involving adultery with the captain and improper relationships with two female Army officers. Adultery is a crime in the military. Sentencing is slated for this week.

The Army originally had intended to prosecute Sinclair for allegedly sexually assaulting the captain while both were deployed to Afghanistan in 2011. The trial played out at a time when the military is struggling to deal with rising numbers of sexual assaults.

But the case began to unravel early last week after the defense received documents, including e-mails from the prosecution, in a request for discovery documents. In a hearing before the trial judge, Col. James Pohl, defense lawyers argued that the communications were clear evidence that a decision to take the case to trial was tainted.

They said they also found proof that the accuser had made conflicting statements in her testimony.

Pohl agreed there had been undue influence. He said that Lt. Gen. Joseph Anderson, previously commander at Fort Bragg, rejected an early plea-bargain offer from Sinclair after Anderson had received a letter from an advocate for the alleged victim urging him to do so.

In that Dec. 17 letter, the advocate, Capt. Cassie Fowler, told Anderson that accepting Sinclair's offer to plead guilty to lesser charges "would only strengthen the arguments of those individuals that believe the prosecution of sexual assault should be taken away from the Army... (It) would send the wrong signal to those senior commanders who would prey on their subordinates."

At the time the letter was sent, Congress was considering a law proposed by Sen. Kirsten Gillibrand, D-N.Y., aimed at removing decisions about sexual assault cases from the military chain of command. That legislation, opposed by the Pentagon, was later narrowly defeated in the Senate.

After his ruling on undue influence, Pohl offered Sinclair the chance to reopen plea negotiations, only with another commanding officer - Chinn.

The result was the agreement signed Saturday.

"We're left with a collection of lesser charges, most of which aren't criminal in the civilian world," Sinclair's lead attorney, Richard Scheff, said in a statement issued Sunday. "Brig Gen. Sinclair has admitted to mistakes that are normally a matter between husbands and wives, or employees and HR departments. It's time to put this matter to rest."

Scheff added: "After wasting millions of taxpayer dollars, the Army finally admitted what it's known for many months: Gen.Sinclair is innocent of sexual assault."